1. Field of the Invention
The present invention relates to a process for producing structural elements, preferably prototypes, in which a "lost" model, i.e., a positive model, of the structural element is produced in a first step, the model is subsequently cast with a molding compound for producing a mold, i.e., a negative model, and the mold then produces the structural element, preferably a prototype, by casting.
2. The Prior Art
Processes of this type, which are preferably employed for producing costly prototypes containing, for example complex cavities, are known from the state of the art. The plaster casting process, in which the molding compound is a gypsum compound, is such a process. In some applications, the so-called "fine casting process" is employed for producing such prototypes instead of using the plaster casting method. The drawback common to these two processes is that they are either not suitable at all for producing prototypes with complex shapes and/or complex cavities, or that they are very expensive.
A process for producing structural elements such as prototypes has become known from German Patent No. DE 195 45 167 A1. This process uses a polystyrene model, which is coated with wax by immersing it in liquid wax. A ceramic sludge is then applied to the surface of the wax. The model is then calcinated and the cavity formed by gassing out the polystyrene is filled by pouring in the molding compound using the fine casting process. In order to permit the manufacture of more complex structural elements by this method, several pieces of the structural elements are first produced in this process, which then have to be assembled into a complete structural element following their immersion in wax. This process is relatively complicated and thus costly, because several components of the structural element have to produced separately.